1. Field of the Invention
The present invention relates to a display apparatus where plural operating systems are operated on a single processor. In particular, the present invention relates to a control method for sharing one and the same display device and to a display apparatus using the control method.
2. Description of the Prior Art
In a conventional display apparatus, i.e., for example, a display apparatus in a navigation apparatus, one operating system is operated. Moreover, the one operating system executes a resource schedule so that it can manage and efficiently operate resources such as a CPU, a memory, and a display.
By the way, there exist various types of operating systems, the examples of which are a type that is superior in a batch processing, a type that is superior in GUI (Graphical User Interface) in office paperwork, a type that is superior in a real time processing, and so forth. In order to extract these plural characteristics, there is the need for wishing to execute plural operating systems simultaneously on one processor. For example, in the navigation apparatus, there is a request for wishing to simultaneously operate an operating system where a development tool has been prepared and the operating system that is superior in the real time characteristic. This request results from the following reason: In the operating system where the development tool has been prepared, communications functions such as the GUI and a mail can be easily developed, whereas in the operating system (which, hereinafter, will be abbreviated as the OS) that is superior in the real time characteristic, a processing such as a map scroll can be processed at a high-speed.